diff --git a/.JuliaFormatter.toml b/.JuliaFormatter.toml
new file mode 100644
index 000000000..323237bab
--- /dev/null
+++ b/.JuliaFormatter.toml
@@ -0,0 +1 @@
+style = "blue"
diff --git a/.github/workflows/CI.yml b/.github/workflows/CI.yml
index 5e31ddcdb..dc73a1d7a 100644
--- a/.github/workflows/CI.yml
+++ b/.github/workflows/CI.yml
@@ -21,7 +21,7 @@ jobs:
           - x86
           - x64
     steps:
-      - uses: actions/checkout@v4.0.0
+      - uses: actions/checkout@v4
       - uses: julia-actions/setup-julia@v1
         with:
           version: ${{ matrix.version }}
diff --git a/.github/workflows/Cancel.yml b/.github/workflows/Cancel.yml
index 85b1ef3d2..652e014a9 100644
--- a/.github/workflows/Cancel.yml
+++ b/.github/workflows/Cancel.yml
@@ -13,7 +13,7 @@ jobs:
   cancel:
     runs-on: ubuntu-latest
     steps:
-    - uses: styfle/cancel-workflow-action@0.9.0
+    - uses: styfle/cancel-workflow-action@0.12.0
       with:
         all_but_latest: true
         workflow_id: ${{ github.event.workflow.id }}
diff --git a/.github/workflows/IntegrationTest.yml b/.github/workflows/IntegrationTest.yml
index f49c7cddf..c63b657c1 100644
--- a/.github/workflows/IntegrationTest.yml
+++ b/.github/workflows/IntegrationTest.yml
@@ -25,14 +25,14 @@ jobs:
         #    package: {user: JuliaDiff, repo: Diffractor.jl}
 
     steps:
-      - uses: actions/checkout@v4.0.0
+      - uses: actions/checkout@v4
       - uses: julia-actions/setup-julia@v1
         with:
           version: ${{ matrix.julia-version }}
           arch: x64
       - uses: julia-actions/julia-buildpkg@latest
       - name: Clone Downstream
-        uses: actions/checkout@v4.0.0
+        uses: actions/checkout@v4
         with:
           repository: ${{ matrix.package.user }}/${{ matrix.package.repo }}
           path: downstream
diff --git a/.github/workflows/JuliaNightly.yml b/.github/workflows/JuliaNightly.yml
index 0d3526c0b..a1281c5f6 100644
--- a/.github/workflows/JuliaNightly.yml
+++ b/.github/workflows/JuliaNightly.yml
@@ -23,7 +23,7 @@ jobs:
           - x86
           - x64
     steps:
-      - uses: actions/checkout@v4.0.0
+      - uses: actions/checkout@v4
       - uses: julia-actions/setup-julia@v1
         with:
           version: ${{ matrix.version }}
diff --git a/.github/workflows/VersionVigilante_pull_request.yml b/.github/workflows/VersionVigilante_pull_request.yml
index 76fffeac4..57ee668e3 100644
--- a/.github/workflows/VersionVigilante_pull_request.yml
+++ b/.github/workflows/VersionVigilante_pull_request.yml
@@ -6,7 +6,7 @@ jobs:
   VersionVigilante:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4.0.0
+      - uses: actions/checkout@v4
       - uses: julia-actions/setup-julia@latest
       - name: VersionVigilante.main
         id: versionvigilante_main
diff --git a/.github/workflows/format.yml b/.github/workflows/format.yml
new file mode 100644
index 000000000..f80377a24
--- /dev/null
+++ b/.github/workflows/format.yml
@@ -0,0 +1,27 @@
+name: Format suggestions
+
+on:
+  pull_request:
+
+concurrency:
+  # Skip intermediate builds: always.
+  # Cancel intermediate builds: only if it is a pull request build.
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: ${{ startsWith(github.ref, 'refs/pull/') }}
+
+jobs:
+  format:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: julia-actions/setup-julia@latest
+        with:
+          version: 1
+      - run: |
+          julia  -e 'using Pkg; Pkg.add("JuliaFormatter")'
+          julia  -e 'using JuliaFormatter; format("."; verbose=true)'
+      - uses: reviewdog/action-suggester@v1
+        with:
+          tool_name: JuliaFormatter
+          fail_on_error: true
+          filter_mode: added
diff --git a/Project.toml b/Project.toml
index 8dfefc100..77f514046 100644
--- a/Project.toml
+++ b/Project.toml
@@ -1,6 +1,6 @@
 name = "ChainRules"
 uuid = "082447d4-558c-5d27-93f4-14fc19e9eca2"
-version = "1.54.0"
+version = "1.58.1"
 
 [deps]
 Adapt = "79e6a3ab-5dfb-504d-930d-738a2a938a0e"
@@ -23,15 +23,21 @@ Adapt = "3.4.0"
 ChainRulesCore = "1.15.3"
 ChainRulesTestUtils = "1.5"
 Compat = "3.46, 4.2"
+Distributed = "1"
 FiniteDifferences = "0.12.20"
 GPUArraysCore = "0.1.0"
 IrrationalConstants = "0.1.1, 0.2"
 JLArrays = "0.1"
 JuliaInterpreter = "0.8,0.9"
+LinearAlgebra = "1"
+Random = "1"
 RealDot = "0.1"
 SparseInverseSubset = "0.1"
+SparseArrays = "1"
 StaticArrays = "1.2"
+Statistics = "1"
 StructArrays = "0.6.11"
+SuiteSparse = "1"
 julia = "1.6"
 
 [extras]
diff --git a/src/ChainRules.jl b/src/ChainRules.jl
index 28e73c166..6d33a22e7 100644
--- a/src/ChainRules.jl
+++ b/src/ChainRules.jl
@@ -43,6 +43,7 @@ include("rulesets/Base/indexing.jl")
 include("rulesets/Base/sort.jl")
 include("rulesets/Base/mapreduce.jl")
 include("rulesets/Base/broadcast.jl")
+include("rulesets/Base/CoreLogging.jl")
 
 include("rulesets/Distributed/nondiff.jl")
 
diff --git a/src/rulesets/Base/CoreLogging.jl b/src/rulesets/Base/CoreLogging.jl
new file mode 100644
index 000000000..ae97f4e40
--- /dev/null
+++ b/src/rulesets/Base/CoreLogging.jl
@@ -0,0 +1,20 @@
+# For the CoreLogging submodule of Base. (not to be confused with the Logging stdlib)
+
+function rrule(
+    rc::RuleConfig{>:ChainRulesCore.HasReverseMode},
+    ::typeof(Base.CoreLogging.with_logger),
+    f::Function,
+    logger::Base.CoreLogging.AbstractLogger,
+)
+    y, f_pb = Base.CoreLogging.with_logger(logger) do
+        rrule_via_ad(rc, f)
+    end
+    with_logger_pullback(ȳ) = (NoTangent(), only(f_pb(ȳ)), NoTangent())
+    return y, with_logger_pullback
+end
+
+@non_differentiable Base.CoreLogging.current_logger(args...)
+@non_differentiable Base.CoreLogging.current_logger_for_env(::Any...)
+@non_differentiable Base.CoreLogging._invoked_shouldlog(::Any...)
+@non_differentiable Base.CoreLogging.Base.fixup_stdlib_path(::Any)
+@non_differentiable Base.CoreLogging.handle_message(::Any...)
diff --git a/src/rulesets/Base/arraymath.jl b/src/rulesets/Base/arraymath.jl
index 7fbf46062..078bb602a 100644
--- a/src/rulesets/Base/arraymath.jl
+++ b/src/rulesets/Base/arraymath.jl
@@ -351,7 +351,7 @@ function rrule(::typeof(\), A::AbstractVecOrMat{<:Real}, B::AbstractVecOrMat{<:R
 
     function backslash_pullback(ȳ)
         Ȳ = unthunk(ȳ)
-        
+
         Ȳf = Ȳ
         @static if VERSION >= v"1.9"
             # Need to ensure Ȳ is an array since since https://github.com/JuliaLang/julia/pull/44358
@@ -360,7 +360,7 @@ function rrule(::typeof(\), A::AbstractVecOrMat{<:Real}, B::AbstractVecOrMat{<:R
             end
         end
         Yf = Y
-        @static if VERSION >= v"1.9" 
+        @static if VERSION >= v"1.9"
             # Need to ensure Yf is an array since since https://github.com/JuliaLang/julia/pull/44358
             if !isa(Y, AbstractArray)
                 Yf = [Y]
@@ -371,7 +371,7 @@ function rrule(::typeof(\), A::AbstractVecOrMat{<:Real}, B::AbstractVecOrMat{<:R
             B̄ = A' \ Ȳf
             Ā = -B̄ * Y'
             t = (B - A * Y) * B̄'
-            @static if VERSION >= v"1.9" 
+            @static if VERSION >= v"1.9"
                 # Need to ensure t is an array since since https://github.com/JuliaLang/julia/pull/44358
                 if !isa(t, AbstractArray)
                     t = [t]
diff --git a/src/rulesets/Base/base.jl b/src/rulesets/Base/base.jl
index 9576abd98..28cc11d19 100644
--- a/src/rulesets/Base/base.jl
+++ b/src/rulesets/Base/base.jl
@@ -94,6 +94,7 @@ end
 
 @scalar_rule fma(x, y, z) (y, x, true)
 @scalar_rule muladd(x, y, z) (y, x, true)
+@scalar_rule muladd(x::Union{Number, ZeroTangent}, y::Union{Number, ZeroTangent}, z::Union{Number, ZeroTangent}) (y, x, true)
 @scalar_rule rem2pi(x, r::RoundingMode) (true, NoTangent())
 @scalar_rule(
     mod(x, y),
diff --git a/src/rulesets/Base/indexing.jl b/src/rulesets/Base/indexing.jl
index 1334cc925..830571ecd 100644
--- a/src/rulesets/Base/indexing.jl
+++ b/src/rulesets/Base/indexing.jl
@@ -1,6 +1,10 @@
 # Int rather than Int64/Integer is intentional
-function frule((_, ẋ), ::typeof(getfield), x::Tuple, i::Int)
-    return x.i, ẋ.i
+function ChainRulesCore.frule((_, Δ, _), ::typeof(getfield), strct, sym::Union{Int,Symbol})
+    return (getfield(strct, sym), isa(Δ, NoTangent) ? NoTangent() : getproperty(Δ, sym))
+end
+
+function ChainRulesCore.frule((_, Δ, _, _), ::typeof(getfield), strct, sym::Union{Int,Symbol}, inbounds)
+    return (getfield(strct, sym, inbounds), isa(Δ, NoTangent) ? NoTangent() : getproperty(Δ, sym))
 end
 
 "for a given tuple type, returns a Val{N} where N is the length of the tuple"
@@ -140,7 +144,7 @@ end
 ChainRules.@non_differentiable _setindex_zero(x::AbstractArray, dy::Any, inds::Any...)
 
 function ∇getindex!(dx::AbstractArray, dy, inds::Integer...)
-    view(dx, inds...) .+= Ref(dy)
+    @views dx[inds...] += dy
     return dx
 end
 function ∇getindex!(dx::AbstractArray, dy, inds...)
diff --git a/src/rulesets/Base/nondiff.jl b/src/rulesets/Base/nondiff.jl
index 58298f068..d35024163 100644
--- a/src/rulesets/Base/nondiff.jl
+++ b/src/rulesets/Base/nondiff.jl
@@ -483,10 +483,6 @@ end
 @non_differentiable Broadcast.result_style(::Any)
 @non_differentiable Broadcast.result_style(::Any, ::Any)
 
-@non_differentiable Base.CoreLogging.current_logger_for_env(::Any...)
-@non_differentiable Base.CoreLogging._invoked_shouldlog(::Any...)
-@non_differentiable Base.CoreLogging.Base.fixup_stdlib_path(::Any)
-@non_differentiable Base.CoreLogging.handle_message(::Any...)
 
 @non_differentiable Libc.free(::Any)
 @non_differentiable Libc.getpid()
diff --git a/src/rulesets/LinearAlgebra/structured.jl b/src/rulesets/LinearAlgebra/structured.jl
index da153d14e..245335774 100644
--- a/src/rulesets/LinearAlgebra/structured.jl
+++ b/src/rulesets/LinearAlgebra/structured.jl
@@ -96,7 +96,7 @@ end
 
 function _diagm_back(p, ȳ)
     k, v = p
-    d = diag(unthunk(ȳ), k)[1:length(v)] # handle if diagonal was smaller than matrix
+    d = diag(unthunk(ȳ), k)[eachindex(v)] # handle if diagonal was smaller than matrix
     return Tangent{typeof(p)}(second = d)
 end
 
diff --git a/src/rulesets/SparseArrays/sparsematrix.jl b/src/rulesets/SparseArrays/sparsematrix.jl
index 8ee8f8cd0..06de7a135 100644
--- a/src/rulesets/SparseArrays/sparsematrix.jl
+++ b/src/rulesets/SparseArrays/sparsematrix.jl
@@ -137,3 +137,26 @@ function rrule(::typeof(det), x::SparseMatrixCSC)
     end
     return Ω, det_pullback
 end
+
+
+function rrule(::typeof(spdiagm), m::Integer, n::Integer, kv::Pair{<:Integer,<:AbstractVector}...)
+
+    function spdiagm_pullback(ȳ)
+        return (NoTangent(), NoTangent(), NoTangent(), _diagm_back.(kv, Ref(ȳ))...)
+    end
+    return spdiagm(m, n, kv...), spdiagm_pullback
+end
+
+function rrule(::typeof(spdiagm), kv::Pair{<:Integer,<:AbstractVector}...)
+    function spdiagm_pullback(ȳ)
+        return (NoTangent(), _diagm_back.(kv, Ref(ȳ))...)
+    end
+    return spdiagm(kv...), spdiagm_pullback
+end
+
+function rrule(::typeof(spdiagm), v::AbstractVector)
+    function spdiagm_pullback(ȳ)
+        return (NoTangent(), diag(unthunk(ȳ)))
+    end
+    return spdiagm(v), spdiagm_pullback
+end
diff --git a/test/rulesets/Base/CoreLogging.jl b/test/rulesets/Base/CoreLogging.jl
new file mode 100644
index 000000000..28c0b74a8
--- /dev/null
+++ b/test/rulesets/Base/CoreLogging.jl
@@ -0,0 +1,11 @@
+# For the CoreLogging submodule of Base. (not to be confused with the Logging stdlib)
+@testset "CoreLogging.jl" begin
+    @testset "with_logger" begin
+        test_rrule(
+            Base.CoreLogging.with_logger,
+            () -> 2.0 * 3.0,
+            Base.CoreLogging.NullLogger();
+            check_inferred=false,
+        )
+    end
+end
diff --git a/test/rulesets/Base/base.jl b/test/rulesets/Base/base.jl
index 36452da1e..9a5278747 100644
--- a/test/rulesets/Base/base.jl
+++ b/test/rulesets/Base/base.jl
@@ -153,6 +153,16 @@
         test_rrule(muladd, 10randn(), randn(), randn())
     end
 
+    @testset "muladd ZeroTangent" begin
+        test_frule(muladd, 2.0, 3.0, ZeroTangent())
+        test_frule(muladd, 2.0, ZeroTangent(), 4.0)
+        test_frule(muladd, ZeroTangent(), 3.0, 4.0)
+
+        test_rrule(muladd, 2.0, 3.0, ZeroTangent())
+        test_rrule(muladd, 2.0, ZeroTangent(), 4.0)
+        test_rrule(muladd, ZeroTangent(), 3.0, 4.0)
+    end
+
     @testset "fma" begin
         test_frule(fma, 10randn(), randn(), randn())
         test_rrule(fma, 10randn(), randn(), randn())
diff --git a/test/rulesets/Base/indexing.jl b/test/rulesets/Base/indexing.jl
index d3c7ecfb4..e878dd061 100644
--- a/test/rulesets/Base/indexing.jl
+++ b/test/rulesets/Base/indexing.jl
@@ -1,3 +1,19 @@
+struct FooTwoField
+    x::Float64
+    y::Float64
+end
+ 
+
+@testset "getfield" begin
+   test_frule(getfield, FooTwoField(1.5, 2.5), :x, check_inferred=false)
+    
+    test_frule(getfield, (; a=1.5, b=2.5), :a, check_inferred=false)
+    test_frule(getfield, (; a=1.5, b=2.5), 2)
+
+    test_frule(getfield, (1.5, 2.5), 2)
+    test_frule(getfield, (1.5, 2.5), 2, true)
+end
+
 @testset "getindex" begin
     @testset "getindex(::Tuple, ...)" begin
         x = (1.2, 3.4, 5.6)
@@ -161,6 +177,14 @@
         @test Array(y3) == Array(x_23_gpu)[1, [1,1,2]]
         @test unthunk(bk3(jl(ones(3)))[2]) == jl([2 1 0; 0 0 0])
     end
+
+    @testset "getindex(::Array{<:AbstractGPUArray})" begin
+        x_gpu = jl(rand(1))
+        y, back = rrule(getindex, [x_gpu], 1)
+        @test y === x_gpu
+        dxs_gpu = unthunk(back(jl([1.0]))[2])
+        @test dxs_gpu == [jl([1.0])]
+    end
 end
 
 # first & tail handled by getfield rules
diff --git a/test/rulesets/SparseArrays/sparsematrix.jl b/test/rulesets/SparseArrays/sparsematrix.jl
index 03f1052c2..283452a8a 100644
--- a/test/rulesets/SparseArrays/sparsematrix.jl
+++ b/test/rulesets/SparseArrays/sparsematrix.jl
@@ -18,6 +18,51 @@ end
     test_rrule(SparseVector{Float32}, Float32.(v), rtol=1e-4)
 end
 
+# copied over from test/rulesets/LinearAlgebra/structured
+@testset "spdiagm" begin
+    @testset "without size" begin
+        M, N = 7, 9
+        s = (8, 8)
+        a = randn(M)
+        b = randn(M)
+        c = randn(M - 1)
+        ȳ = randn(s)
+        ps = (0 => a, 1 => b, 0 => c)
+        y, back = rrule(spdiagm, ps...)
+        @test y == spdiagm(ps...)
+        ∂self, ∂pa, ∂pb, ∂pc = back(ȳ)
+        @test ∂self === NoTangent()
+        ∂a_fd, ∂b_fd, ∂c_fd = j′vp(_fdm, (a, b, c) -> spdiagm(0 => a, 1 => b, 0 => c), ȳ, a, b, c)
+        for (p, ∂px, ∂x_fd) in zip(ps, (∂pa, ∂pb, ∂pc), (∂a_fd, ∂b_fd, ∂c_fd))
+            ∂px = unthunk(∂px)
+            @test ∂px isa Tangent{typeof(p)}
+            @test ∂px.first isa AbstractZero
+            @test ∂px.second ≈ ∂x_fd
+        end
+    end
+    @testset "with size" begin
+        M, N = 7, 9
+        a = randn(M)
+        b = randn(M)
+        c = randn(M - 1)
+        ȳ = randn(M, N)
+        ps = (0 => a, 1 => b, 0 => c)
+        y, back = rrule(spdiagm, M, N, ps...)
+        @test y == spdiagm(M, N, ps...)
+        ∂self, ∂M, ∂N, ∂pa, ∂pb, ∂pc = back(ȳ)
+        @test ∂self === NoTangent()
+        @test ∂M === NoTangent()
+        @test ∂N === NoTangent()
+        ∂a_fd, ∂b_fd, ∂c_fd = j′vp(_fdm, (a, b, c) -> spdiagm(M, N, 0 => a, 1 => b, 0 => c), ȳ, a, b, c)
+        for (p, ∂px, ∂x_fd) in zip(ps, (∂pa, ∂pb, ∂pc), (∂a_fd, ∂b_fd, ∂c_fd))
+            ∂px = unthunk(∂px)
+            @test ∂px isa Tangent{typeof(p)}
+            @test ∂px.first isa AbstractZero
+            @test ∂px.second ≈ ∂x_fd
+        end
+    end
+end
+
 @testset "findnz" begin
     A = sprand(5, 5, 0.5)
     dA = similar(A)
@@ -42,4 +87,4 @@ end
     test_rrule(logabsdet, A)
     test_rrule(logdet, A)
     test_rrule(det, A)
-end
\ No newline at end of file
+end
diff --git a/test/runtests.jl b/test/runtests.jl
index a9f25c55c..768f7c208 100644
--- a/test/runtests.jl
+++ b/test/runtests.jl
@@ -53,6 +53,7 @@ end
     test_method_tables()  # Check the global method tables are consistent
 
     # Each file puts all tests inside one or more @testset blocks
+    include_test("rulesets/Base/CoreLogging.jl")
     include_test("rulesets/Base/base.jl")
     include_test("rulesets/Base/fastmath_able.jl")
     include_test("rulesets/Base/evalpoly.jl")
diff --git a/test/unzipped.jl b/test/unzipped.jl
index 97aaa23f5..4215f3a6e 100644
--- a/test/unzipped.jl
+++ b/test/unzipped.jl
@@ -87,11 +87,14 @@ using ChainRules: unzip_broadcast, unzip #, unzip_map
         # TODO invent some tests of this rrule's pullback function
 
         @test unzip(jl([(1,2), (3,4), (5,6)])) == (jl([1, 3, 5]), jl([2, 4, 6]))
-
         @test unzip(jl([(missing,2), (missing,4), (missing,6)]))[2] == jl([2, 4, 6])
-        @test unzip(jl([(missing,2), (missing,4), (missing,6)]))[2] isa Base.ReinterpretArray
-
         @test unzip(jl([(1,), (3,), (5,)]))[1] == jl([1, 3, 5])
-        @test unzip(jl([(1,), (3,), (5,)]))[1] isa Base.ReinterpretArray
+
+        # depending on Julia/package versions, may get ReinterpretArray or JLArray
+        # Either is acceptable
+        @test isa(
+            unzip(jl([(missing, 2), (missing, 4), (missing, 6)]))[2],
+            Union{Base.ReinterpretArray,JLArray},
+        )
     end
-end
\ No newline at end of file
+end